Raman spectroscopy study of the influence of additives (Cr-, Cr/Al-, and Gd) on UO2 dissolution behavior

Abstract In this work, Raman spectroscopy (RS) has been used to study the behavior of spent nuclear fuel (SNF) under disposal conditions. In particular, evolutionary Accident-Tolerant Fuels (ATFs) consisting in UO 2 doped with Cr and Cr/Al; as well as neutron absorbers (UO 2 doped with Gd), has been manufactured and studied. The prepared pellets have been exposed to three different pH leachants (inert media, carbonated media, and young cement water with calcium) for distinct times. RS analyses have been conducted in both the leached and the unleached pellets. The results show that the addition of Cr, and Cr/Al does not lead to a noteworthy change of the pellet surface under the three media considered. Gd doping induces a higher intensity of the so-called “defects band,” which is not dramatically affected after leaching. No secondary phases have been observed. These results are in good agreement with previous studies by XRD and SEM, thus validating RS as an accurate analytical technique. Graphical abstract